hey there people.. so i woke up today hopped in my car and my check engine light was on.. first thing i did was drive it to advance to check out why it was on... it came up as EVAP Emission Control Leak (large)...
the dude said it usually is a gas cap... well i checked that and its seal is intact and good... anyone have any tips on what else i could check or fix..
is this bad for my car if i continue driving it for a bit intill i figure it out? or does it not matter.

btw i have a 1998 a4 2.8l avant quattro .. thx for any help.
-dom

 

The cap can still be bad or you left it loose.
An easy way to check the gas cap would be to get you nose as close as you can to the fuel door and quickly open the door and see if you can smell gas, if you smell any gas the cap is faulty.
It won't hurt the engine to drive around on an emmisions related fault code though.

 

Usually the only other possibilities for large leaks other than the gas cap are damaged charcoal canisters or rubber evap lines that have been chewed though by small furry creatures.

 

sweet deal... i might as well just get a new gas cap anyways just to see if it will change... thanks for the quick respone tech79

any other ideas will be considered..
thx again, these forums are awesome.. have a good day to all

 

Post the code. The other issues are the small grey and white check vavle behind the airbox that rubs against a metal clip, or the EVAP valve itself (also cheap 55 bucks)

 

Check the purge valve and hoses/check valves right behind the airbox. Maybe one of them came loose or broke off.

If the problem isn't there, then it's probably in the back of the car (gas cap, charcoal canister, EVAP leak detection pump, or the lines running to/from these items).

Also, see my thread from a few months ago with pics: https://www.audiforums.com/m_498727/tm.htm